<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>zy</title>
		<style>
			#txt{
				width: 600px;
                margin: auto;
				text-align: center;
				color: chartreuse;
			}
		</style>
	</head>
	<body>
		<div id="txt"></div>
		<script>
			for( i = 0 ; i < 10 ; i++){
				for(var j = 0 ; j < i ; j++ ){
				document.getElementById("txt").innerHTML +="☆";
				}
				document.getElementById("txt").innerHTML +="<br/>";
			}
		</script>
		
	</body>
</html>
